Apparatus for producing filaments of uneven denier



March 16, 1954 c w GAYLER 2,671,929

APPARATUS FOR PRODUCING FILAMENTS OF UNEVEN DENIER Filed NOV. 5, 1949 L a E INVENTOR.

cATc/L w. 6A YL 5/? ATTORNEY.

Patented Mar. 16, 1954 APPARATUS FOR PRODUCING FILAMENTS F UNEVEN DENIER Cecil W. Gayler, Ridley Park, Pa., assignor to American Viscose Corporation, Wilmington, Del., a corporation of Delaware Application November 3, 1949, Serial No. 125,179

1 Claim.

This invention relates to apparatus for extruding yarns of irregular denier and particularly to apparatus for driving a positive displacement pump for such apparatus.

Various arrangements have been used to obtain filamentary material of irregular denier commonly referred to as thick and thin filaments and involve such means as intermittently operated plungers in the feed line carrying a liquid filament-forming material, cutting away part of the gear teeth in a pump which supplies the liquid material, removing the filament from the jet at varying speeds, or alternately operating a pump from driving members operating at different speeds.

It is an object of the present invention to provide a simplified and serviceable apparatus for spinning filamentary material of irregular denier having general applicability to all types of liquid filament-forming materials including those which are provided in a molten condition as they are passed through a spinneret, liquid solutions which are coagulated in a spinning bath as they pass from a spinneret, and solutions of resins which may be extruded as small streams of liquid to form filaments when a volatile solvent evaporates therefrom. It is another object to provide an apparatus having adjustability with respect to the number of thick and thin sections of the filaments produced per revolution of a positive displacement pump used to force the filamentforming liquid through a spinneret. It is still another object to provide an apparatus which irregularly spaces the thick and thin sections of the filament so as to avoid the production of pattern effects in a fabric. It is also an object to provide an apparatus which is free from reciprocating parts, plungers, diaphragms, complicated timing mechanism and the like. Other objects, features and advantages of the invention will be apparent from the following description of the invention and the drawing relating thereto in which:

Fig. 1 is a pictorial view with portions broken away illustrating apparatus for forcing a filament-forming material through a spinneret;

Fig. 2 illustrates a set of one type of gears used to transmit drive to a positive displacement pump;

Fig. 3 illustrates a set of another type of gears which may be employed in lieu of the gears in Fig. 2;

Fig. 3a illustrates a set of still another type of gears which may be used to drive a pump included in spinning equipment;

Fig. 4 illustrates a gear chain arrangement for transmitting the drive from a motor to a pump;

Fig. 5 illustrates a modified gear chain arrangement; and

Fig. 6 illustrates a drive transmission comprising sprockets and chains.

Briefly, the invention comprises an apparatus for producing filaments having closely spaced sections of substantial variation in denier wherein a chain of rotary driving members containing members of non-circular shape is used to drive a positive displacement pump which forces a liquid filament-forming material through a spinneret.

Fig. 1 illustrates apparatus of which a pump Iii receives a filament-forming liquid through a line i2 and discharges it through a line I3. The liquid is forced through a spinneret i5 in small streams which may be treated in any desired manner to form filaments. For example, treatment of such streams as they are discharged from the pump, if they are a melted material, will consist of cooling the filaments by passing them into a cooling liquid or gaseous medium; if the liquid is a solution of filament-forming resin in a volatile solvent, the solvent is evaporated from the streams to form filaments and the solvent vapor may be withdrawn from a hood 11. If the streams comprise coagulable liquid, such as viscose solution, they are passed into a conventionally prepared spinning bath.

The pump I0 is any conventional positive displacement type, such as the two-gear pump illustrated, which is suitable for handling such filament-forming liquids as melted polyamides, or vinyl resins. The pump is fabricated from suitable alloys and constructed with the tolerances or clearances needed to adapt the pump to high temperature operation. One of the internal gears of the pump is mounted on a shaft protruding through a side wall of the pump to support an exterior gear l9.

As shown in Fig. 1, an external gear 19 is driven by a gear 20 mounted on a shaft extending through the wall of gear reduction unit 22. The gears l9 and 20 are'of the square" type illustrated in Fig. 2, although other types of non circular or polygonal gears may be used. The gear reduction unit 22 is driven by such means as an electrical motor 24 secured to the unit. The drive may be transmitted from the shaft of the motor to the power receiving shaft of the unit by a pair of meshing gears or by the chain and sprocket drive 26 illustrated. The gear reduction unit 22 is a conventional step-down unit 3 containing a number of gears in series in a desired combination to obtain the desired ratio in the speeds of rotation of the motor 24 and the internal gears of the pump 12.

A set of matching elliptical gears 26 and 27, such as shown in Fig. 3, may be substituted for the gears l9 and 20 of Fig. 1 to transmit the drive from the unit 22 to the pump I0. Gears of the elliptical type have an advantage over the polygonal type gears of Fig. 2 in that they may be constructed in considerable variety, each pair difiering from other pairs in the ratios of their maximum and minimum radii even though a specific spacing of the axes of rotation for the gears is maintained. By providing a pair of gears havin a suitable ratio between maximum to minimum radii, a desired ratio may be established in the denier of adjacent thick and thin sections produced from the apparatus in which the drive is transmitted through the gears. The range of ratio at one extreme would be limited to circular gears having exactly centered axes of rotation; at the other extreme, the range of ratio would be limited by the proximity of the bore for the shaft to the rim section from which the teeth of the gear extend consistent with sufficient strength in the gear to transmit the drive. Two types of elliptical gears are illustrated. In the type illustrated by Fig. 3, the hubs are off-center and the major axes (also the minor axes) of the gears always point in a similar direction, and similar axes rotate into alignment once during every revolution. The driven gear passes through one speed variation cycle per revolution of the driving gears. which is illustrated by Fig. 3a have centered hubs and are meshed so that the major axis of one comes into alignment with the minor axis of the other, or conversely, during each revolution of the gears. The driven gear of Fig. 3a passes through two speed variation cycles per revolution of the driving gear.

The apparatus illustrated in Fig. 1 includes a pair of non-circular gears for driving the pump iii. Apparatus of this type will produce regularly spaced thick and thin sections in the filamentary material. However, regular spacing promotes the formation of pattern effects in fabric which may or may not be desired. In the event the patterns are not desired, the power may be transmitted between a pump and a driving means through a gear train such as illustrated in 4 containing two sets of non-circular gears 28 and 29 to produce irregularity in the spacing of thick and thin sections linearly of the filaments. To prevent synchronism occurring between the two sets of non-circular gears, a pair of circular gears 30 are included in the gear train between the two sets of non-circular gears.

The circular gears may have relative sizes in any ratio consistent with obtaining a desired speed reduction in the gear train but the ratio of sizes is not such that teeth of the one gear divide evenly into the teeth of the other gear. Preferably, the number of teeth on the one gear vary by one or two teeth from a number which divides evenly into the number of the teeth of the other gear. By interposing a set of such circular gears between two sets of non-circular gears, synchronous or cyclical relationships may be avoided between the two sets of non-circular gears which produce regularity in the spacing of adjacent thick and thin sections of the filaments. It is possible for the two setsof non-circular gears to rotate into a similar relationship after a considerable number of rotations of the set nearest The other type of elliptic gears the driving means. However, by proper selection of the set of circular gears, recurrence of a similar spacing of the filament sections can be avoided in as many as 20 to 40 revolutions of the pump gears to obtain a variation cycle extending over a similar number of consecutive thick or thin sections of the yarn. v Such a distribution is sufficient variation in the spacing of the adjacent thick or thin sections to prevent the appearance of any pattern efiects in the fabric.

It is desirable in the practice of this invention to be able to vary the number of thick or thin. sections produced per revolution of the pump. Such variations may be obtained by a gear train, illustrated in Fig. 5, comprising three sets of meshing gears. The middle set of gears 32 are non-circular such as shown in Figs. 2 and 3. The sizes of the circular gears may be varied in both sets (40 and M) to speed up or slow down the rotation of the non-circular gears while maintaining a specific average speed of rotation of the pump and maintaining the motor 24 at a constant speed. By this expedient, changes in the number of thick and thin sections per revolution of the pump are obtained. For example, if it is desired to increase the number of thick and thin sections per revolution of the pump, a

gear ratio is selected for the set 48 which, in

effect, increases the number of revolutions of the non-circular gears 32 to maintain the rotational speed of the pump it. However, a suitable set of speed-increasing gears 4| is selected which compensates for the loss of speed sustained by the installation of the speed-reducing gear et 40. Conversely, when a set of speedincreasing gears 40 is used, which in effect, decrease the number of thick or thin sections per revolution of the pump, the pump speed may be established at a desired average rat by replacing the gears 4| with a set of gears having such a ratio as to bring about a speed reduction equal to the speed-increasing effect of th gears 44. The gear system of Figs. 4 and 5 may be combined to obtain irregularity in the spacing of the thick and thin sections and to control the average distance between the sections by having a gear train comprising two sets of circular gears alternately positioned in series with two sets of non-circular gears wherein the circular gears may be changed as described with respect to Fig. 5.

The drive transmission unit of Fig. 6 is similar to that of Fig. 5 in its effect on the pump E!) but differs structurally in that the gears 32, M, and M of Fig. 5 have been replaced by sprockets 32a, 40a, and 41a of corresponding sizes, and the sprockets in adjacent driving relationship connected by chains. In th practice of the present invention, sprockets and chains may be readily substituted for gears which mesh. The use of sprockets and chains may be found to be advantageous in some cases because of the greater selection in the relative sizes of sprockets permitted over gear sets which must mesh and must be constructed according to a specific shaft spacing.

While preferred embodiments of the invention have been shown and described, it is to be understood that changes and variations may be made without departing from the spirit and scope of the invention as defined in the appended claim.

I claim:

In an apparatus for producing varying denier filamentary material comprising a spinneret, a positive displacement pump for feeding the spin- 5 6 neret, a pump shaft, a driv shaft and means divisible into the working periphery of the other for operatively connecting said shafts, that imcircular member. provement wherein said means comprises a series CECIL W. GAYLER.

of rotary members including two pairs of noncircular members wherein the members of each 5 References Clted 1n the file 0f thlS Patent pair are in adjacent driving relationship, said UNITED STATES PATENTS series including also a pair of circular members in series driving relationshp with and between Number Name Date the pairs of non-circular members, the working 1,995,795 Dreyfus a1. Apr. 9, 1935 periphery of on circular member being unevenly 10 2,143,236 Blrk J 1939 

